2007 Lexus RX 400h Review

2007 Lexus RX400h

DRIVING DOWN THE ROAD
WITH CAREY RUSS

2007 Lexus RX 400h

The Lexus RX400h debuted early in model year 2006 as the premium
model of the RX lineup, in an interesting, and unusual, part-time all-wheel
drive form. While a 3.3-liter, 208-horsepower gasoline engine and
167-horsepower electric motor drove the front wheels, the rear wheels were
electrically-powered only, by a 68-horsepower motor. Maximum power was
rated as 268, said by Lexus to be equivalent to a 4.0-liter V8, hence the
RX 400h nameplate.

The market for a high-tech luxury crossover SUV is healthy, as
nearly 30,000 examples were sold in its first full year on the market. Many
cars get standard equipment and trim package changes for their second year,
but the RX hybrid's changes may seem unusual. It's apparently been
decontented. The RX 400h line goes from one fully-equipped premium model to
a lineup more closely aligned with the gasoline-only RX 350 in standard and
optional equipment levels. There is a new front-wheel drive only model, and
many features previously standard are now optional. The result - lower
prices, and a lineup that can appeal to more people. In the Toyota/Lexus
world, hybrids are not only for high-tech early adopters, they will
eventually be mainstream vehicles for everyone. The RX 400h model
realignment should help expand its appeal.

I just spent a week with a 2007 RX 400h. Press fleet spec being
what it usually is, it was not an "entry-level" front-wheel drive model,
but a well-equipped all-wheel drive model. Still, both the base and
as-delivered prices were significantly less than those of the 2006 model I
drove a year ago, with negligible negative impact on its luxury level. As
always, it was exceptionally quiet, smooth, and comfortable, with no
shortage of power when needed. In steady-state, light-throttle operation,
it often ran under pure electric power at speeds up to 35mph, at which time
it was uncannily quiet. At 24 mpg in a week with plenty of high-speed
freeway driving - not the best environment for hybrid fuel economy - it was
still more economical than any similarly-sized gasoline SUV. Hybrids work
well, and for more than small commuter cars.

APPEARANCE: Differences between the hybrid RX 400h and the
regular RX 350 are minimal on the outside. Look for a slightly different
grille, and a small extra opening in the front bumper. It also has front
foglamps and LED taillights. New badging with blue highlights starts a
Lexus trend.

COMFORT: As outside, interior differences between the gasoline
and hybrid versions of the RX are minimal, especially with the standard
equipment realignments. The battery pack is located under the rear seat,
and all that can be seen are vents in the solid underseat area. Leather
upholstery, a roof rack, a power tilt and telescope steering wheel, a
moonroof, and memory settings for the driver's seat, steering wheel, and
outside mirrors are now optional, and make up the Premium Package with
which my test vehicle was equipped. The touch-screen navigation system is
also now an option, included here. The front passenger seat now has
standard power lumbar support, in addition to the usual power
adjustability. As equipped, the RX h is a wonderfully comfortable and
well-equipped luxury vehicle; in standard trim it wouldn't be all that less
luxurious. Seat comfort, front and rear, is first-rate, as is cargo space.

SAFETY: Besides the usual complement of front, front side, and
side curtain airbags, and a driver-side knee airbag, the RX400h has Lexus's
Vehicle Dynamics Integrated Management (VDIM) system. VDIM through
electronically-controlled brakes, integrates braking, traction control, and
Vehicle Stability Control (VSC) system functions with the electronic
throttle control, electric power steering, and regenerative braking systems
to improve driver control of the vehicle. A tire-pressure monitoring system
is new this year.

RIDE AND HANDLING: As with the RX 350, don't look for rugged
off-road ability in the RX 400h, but that hasn't bothered RX buyers, as the
gas versions have been best-sellers for Lexus. The fully-independent
MacPherson strut front, dual-link strut rear suspension is tuned a little
more firmly than that of the RX 350, but it still emphasizes luxury comfort
over sportiness. Add the quiet of the drivetrain, and the RX 400h is a very
relaxing vehicle in which to cover distance.

PERFORMANCE: Any assumptions that a hybrid system is
appropriate only for a small, high-mileage ``economy car'' can be laid to
rest with one short drive in an RX400h. If power is required, simply press
the accelerator to the floor and power is delivered, strongly. At that
time, the 3.3-liter twincam, 24-valve V6 engine audibly makes its presence
known, but most of the time it is nearly as silent as the electric motors.
Other than when the gasoline engine comes on strong when acceleration is
needed at highway speeds, or when torque from the electric motors kicks in
at lower speeds, it's nearly impossible to tell where the power is coming
from without sneaking a peek at the display in the instrument panel, and
operation of the rear motor is completely transparent. The Hybrid Synergy
Drive system used in the RX400h is similar to that in the Prius, but like
in the RX's cousin Toyota Highlander Hybrid, modified for a larger, more
powerful engine and front and (if so equipped) rear motor-generators.

The engine makes a maximum of 208 horsepower at 5600 rpm, with 212 lb-ft
of torque at 4400 rpm. The front motor makes 167 horsepower at 5600 rpm and
247 lb-ft of torque from zero to 1500 rpm - just the ticket for fast
acceleration when needed. They are coupled through a planetary gear
continuously-variable transmission, which is controlled by computers and
motor-generator 1, which is also the starter motor. A second motor, with 68
hp from 4610 through 5120 rpm and 96 lb-ft of torque from zero to 610 rpm,
runs the rear wheels when the control computer decides extra rear traction
is needed. Around town, the RX operates electrically as much as possible,
with the gas engine stopping when the car is stopped and assisting the
electric motor(s) when moving. On the highway, the motors assist the
engine. Note that the engine and motors never develop maximum power at the
same time, but still, maximum system horsepower is listed at 268, not bad
at all. Computers control the show, and it works smoothly and efficiently.
If the real-world 24 mpg I averaged was less than the EPA rating, it was
still better than anything from a similarly-sized internal combustion
vehicle.

CONCLUSIONS:The Lexus RX 400h shows that luxury and utility can have a low environmental impact, and changes to its standard and optional equipment levels for 2007 should increase its appeal.

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